HRE recently had an opportunity to get their hands (and wheels) on a 2015 Mustang.
They managed to test fit a set of HRE P101 Satin Black wheels on the prepro car [see photos]. Specs of the wheels/tires as follows:
HRE P101 in Satin Black
20×10 front
20×11 rear
Nitto NT05 275/35-20 front
Nitto NT05 315/35-20 rear
HRE noticed there being some additional room to go wider tires in the front — something like 295 (285 looks clear).
Check out the test fit photos INSIDE.